Shouldn't the suction line filter be replaced within 24 hours of the initial installation of said filter?

no! , not necessarily i usually let it run for a week then return to check it over and see how the filter/dryer looks .... also there are different types of filter/dryers but their behaviors are the same remove ( capture, absorb) moisture and particles in the system. and they should always be changed because like a sponge they can only do their job to certain capacity.

10-08-2011, 10:55 PM

bunny

Quote:

Originally Posted by jeremyhall.tech.sc

once the moisture is absorbed by the molecular sieve beads it is not released , ever...

the filter should be changed and changed and changed , until the system is totally contaminate free...

In my own experience the media my need to be changed as many as 5 times (ike!) and putting a filter in without the intention of checking and replacing it once it has absorbed and effectively filtered the particles and moisture is no worse than not having one installed in the first place..

A sponge will absorb moisture. Dessicants will adsorb moisture....quite a different process. The moisture is removed molecularly, and held to the surface of the dessicant by a weak chemical bond.

It is an inaccurate statement to say that molecular sieve will never release moisture. Every filter-drier core goes through an activation process prior to completion of the manufacturing process. This process has the cores placed in an oven at an elevated temperature to drive out the moisture the sieve adsorbed during its time exposed to the atmosphere.

Also, when the filter-drier sees a temperature increase in a working system, its water capacity will be reduced. So, if the filter-drier had adsorbed enough water at 70F such that it was near its rated water capacity, a temperature increase would cause the excess moisture above the filter-drier's new (and lower) water capacity to be released back into the system.

Likewise, when the filter-drier experiences a temperature drop (during the night, for example) it will remove some of that water that was previously released back into the system.

10-08-2011, 11:16 PM

jeremyhall.tech.sc

Quote:

Originally Posted by bunny

A sponge will absorb moisture. Dessicants will adsorb moisture....quite a different process. The moisture is removed molecularly, and held to the surface of the dessicant by a weak chemical bond.

It is an inaccurate statement to say that molecular sieve will never release moisture. Every filter-drier core goes through an activation process prior to completion of the manufacturing process. This process has the cores placed in an oven at an elevated temperature to drive out the moisture the sieve adsorbed during its time exposed to the atmosphere.

Also, when the filter-drier sees a temperature increase in a working system, its water capacity will be reduced. So, if the filter-drier had adsorbed enough water at 70F such that it was near its rated water capacity, a temperature increase would cause the excess moisture above the filter-drier's new (and lower) water capacity to be released back into the system.

Likewise, when the filter-drier experiences a temperature drop (during the night, for example) it will remove some of that water that was previously released back into the system.

im going to politely disagree until you show my the error of my logic.

do you have a link or supporting study to support your argument?

i understand that you took the sponge example literally and that would be correct it is chemical, however my point was that a filter/dryer has its limitations...

A sponge will absorb moisture. Dessicants will adsorb moisture....quite a different process. The moisture is removed molecularly, and held to the surface of the dessicant by a weak chemical bond.
.

I just replaced a compessor on an approximately10yr old 6 ton split AC unit last week. It had the factory LL filter installed inside the CU, but another LL filter installed outside the CU. Based on your very informative description, would this second filter have helped the system or have been detrimental?

10-09-2011, 12:10 AM

shamgar

4 more posts and I might have an opinion.

10-09-2011, 10:58 AM

bunny

I'd say a 10 year old filter-drier ought to be removed, and two liquid filter-driers isn't a good idea....extra pressure drop.

Mfgs don't make it convenient to change their factory installed filter-driers, given their location upstream of the liquid shutoff valve...hence they don't get changed when they should.

10-09-2011, 06:56 PM

catmanacman

Quote:

Originally Posted by bunny

I'd say a 10 year old filter-drier ought to be removed, and two liquid filter-driers isn't a good idea....extra pressure drop.

Mfgs don't make it convenient to change their factory installed filter-driers, given their location upstream of the liquid shutoff valve...hence they don't get changed when they should.

I would cut out both drier and put one in the liquid line outside the unit . on the factory driers that are hard to get to I usually put a piece of pipe in the unit and install the drier outside .

10-10-2011, 12:27 AM

surenuff

As some have stated, always change the filter drier if the system has been opened. Yes, a filter will release moisture with too much heat. This is the reason for cutting out, not sweating out a drier to replace it.

10-14-2011, 09:49 PM

james32

that is a golden rule open system = new filter drier i would call company back and ask them y and see what they say :bump: